New blood test may predict Alzheimer's disease

Australian scientists say they are one step closer to creating a blood test that can predict Alzheimer's years before symptoms appear.

New CSIRO research has identified markers in the blood that can signal whether the disease is starting to developing in the brain.

Researchers tested 273 people and found that changes in the blood and brain scans matched with more than 80 per cent accuracy.

There are no drugs that can slow the progression of Alzheimer's disease, but doctors say finding patients before symptoms appear is very important.

Dr Noel Faux from the Florey Institute for Neuroscience and Mental Health says the progressive build-up of the toxic protein amyloid beta is one of the earliest changes associated with the development of Alzheimer's disease.

"Amyloid beta levels become abnormal about 17 years before dementia symptoms appear," he said.

"This gives us a much longer time to intervene to try to slow disease progression if we are able to detect cases early."

CSIRO scientist Dr Samantha Burnham says a blood test is an accessible form of screening for the disease.

"We're hoping that in a few years, maybe five to 10 years, that we could be able to roll this out as frontline screening for Alzheimer's disease, giving those at risk a much better chance of receiving treatment earlier, before it's too late to do much about it," she said.

One quarter of a million Australians currently suffer from dementia and Alzheimer's is the leading cause.

By 2050, it is predicted that one million people will have the disease.

One of them is Lyn Gravolin, who was diagnosed with dementia more than a decade after her family started noticing she had memory problems.

Her husband Alan says that was too late.

"If we had been able to know what was happening right from the start we would have been able to plan our life together knowing that things were going to be changing," he said.

Alzheimer's Australia spokesman John Watkins says treating the disease early could delay its onset by years.

"If we can identify people early this may be a window where we can actually modify the course of the disease," he said.

"We could get them on to medication, and preventative measures that may delay the development of this disease, even by up to five years, would be fantastic outcome."